Rationality is systematized winning

From Lesswrongwiki

You may try to name the highest principle with names such as “the map that reflects the territory” or “experience of success and failure” or “Bayesian decision theory”. But perhaps you describe incorrectly the nameless virtue. How will you discover your mistake? Not by comparing your description to itself, but by comparing it to that which you did not name.

The point of all this discussion of rationality is to actually achieve truer beliefs and more effective actions. It's not some arbitrary social fashion; there are actual criteria of success. It is for this reason that it is written that rationalists should win. If some particular ritual of cognition—even one that you have long cherished as "rational"—systematically gives poorer results relative to some alternative, it is not rational to cling to it. The rational algorithm is to do what works, to get the actual answer—in short, to win, whatever the method, whatever the means. If you can detect a systematic mistake in your thinking, then fix it; if you can see a better method, then adopt it.